Fastening device.



P. H. RICHARDS FASTENING DEVIGE. APPLICATION FILED JUNE 7, 1901. RENEWEDJULY 19, 1906.

926,768. Patented July 6, 1909.

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FRANCIS H. RICHARDS, OF HARTFORD, CONNECTICUT.

FASTENING DEVICE Specification of Letters Patent.

Patented July 6, 1909.

Application filed June 7, 1901, Serial No. 63,516. Renewed July 19,1905. Serial No. 270,437.

T 0 all whom it may concern:

Be it known that I, FRANCIS Il'. Bren- ARDS, a citizen of the UnitedStates, residing at Hartford, in the county of Hartford and State ofConnecticut, have invented certain new and useful Improvements inFastening Devices, of which the following is a specili cation.

This invention relates to devices for securing machine and kindred partsfixedly together, and is especially directed toward the furnishing of afastening device for use in assembling shafts and parts carried thereonin machines where precision in the relative position of the securedparts is desired.

It is a further object of the invention to provide a fastening deviceadapted to be made in very small sizes with a high degree of precision,and also at a low cost of manufacture.

This invention constitutes an improvement upon a fastening devicedisclosed in my application Serial No. 37,420, filed November 23, 1900,in which there is shown, described and claimed a device for securinmachine parts together. The invention set forth in the applicationreferred to embedies a locking piece or element of peculiar form andconstruction, and which, in the organization therein shown anddescribed, is seated in an opening extending longitudinally of the shaftto which the second memher is attached, this opening being made partlyin each of the two members secured together. Qrdinarily, therefore, astherein set forth, the opening for the reception of the locking pieceextends lengtlnvisc of the shaft, and the part of such opening in thelatter terminates in a shoulder. in the present improvement, however,the. organization is such that the opening or recess in which thelocking piece or element is seated extends transversely to that openingin the secured member in which the shaft is located when the parts areassembled. Thus the present improvement provides a twopart fasteningdevice of such a nature that both recesses or openings (that for theshaft and that for the locking piece) are adapted to extend entirelyacross or through the respective parts, facilitating thereby thenecessary machining or other treatment of the parts to fit them fortheir connection. The present improvement also provides an opening forthe reception of the locking piece or element, which is smooth and trulycylindrical as distinguished from the corresponding opening in myhereinbcfore-mentioned device, in which the opening or cavity is shownas provided througlunit with threadsections, although it will beunderstood that in the form of the Connecting device shown in thatapplication it is not essential that these thread-sections be allpresent.

In the drawing accom nmying the present specification, Figure 1illustrates my present improvement as applied to the securing of a crankor arm to a shaft. lfig. 2 is an end clevation of the parts shown inFig. 1, looking along the shaft. I on the plane of the line 3-3 inFig. 1. Fig. 4 is a longitudinal section of the crank or arm, the plane.of the section corresponding to the axis of the opening in the armthrough which the shaft is adapted to extend, and this figure showingparticularly the relation of the openings in the crank or arm, one forthe reception of the shaft and the other for the reception of thelocking piece or element. Fig. 5 is a section of the arm or crank shownin the preceding figures, the plane of the section being that indicatedby the line 5-5 in Fig. 4. Fig. 6 is an elevation of a portion of theshaft constituting one of the illustrated connected members, this figureshowing the shaft as removed from the arm and indicat ing the recess inthe shaft in which the locking piece or element is adapted to fit. Fig.7 is a section on the plane of the line 7*? in lfiig. 6. Fig. 8 is anclevatioual view of the locking piece or element shown in Fig. 8, thesame being removed from its assembled position.

Similar characters of reference designate corresponding parts in allfigures.

The fastening device of this invention, as of that disclosed in myliereinbefore-menlioncd application, may be said to comprise cylindricaland conical surfaces so combined with relation to each other and totheir respcctive cot'iperative surfaces that the reliability of thefastening device, considered as a whole, is independent of theparticular position, within limits, in which the two parts or membersare placed for the purpose of being secured one to the other. Theconical surface mentioned, cooperating with its opposed surface in theuse of the device, results in a wedging or binding of the parts inplace, while the aforesaid cylindrical surface is so disposed withreference to the other surfaces as to render an cl'lectrvc bind- Fig. 3is a sectional view ing action to a considerable degree independent ofthe relative position of the parts one to the other.

Entering upon a more detailed description of the embodiment of theinvention i1lus trated, S designates a shaft and N a crank or armsecured together by means of a device embodying the present invention;these particular parts, it will be understood, are chosen merely forillustrative purposes.

R designates a locking piece or element whose surfaces constitute, inthe preferred form of the invention, the before-mentioned operativeconical and cylindrical surfaces for effecting the locking of the parts.These surfaces are combined in such a way that the locking piece orelement is practically a cylindrical one. The conical surface,cooperating with a proper surface, effects the looking of the parts byreason of the longitudm movement of the locking piece or element. Thereaction surface receives the lateral thrust due to the slight lateralmovement of the locking piece when urged to position. Qne or both ofthese surfaces is preferably spirally arranged upon the locking piece.They are here shown as both arranged in this manner. The cavity oropening, see 2, for the reception of the locking piece extendstransversely to the axis of the shaft S and preferably entirely throughthe crank, arm or other part connected thereto, as the forming of athrough opening in the arm, etc., will facilitate the making thereof.This opening is a straight openingthat is, a bored or drilledopening-and, furthermore, it is not material whether the locking elementfits snugly therein or not. Likewise the opening 3 in the arm for thereception of the shaft S, and which, it will be noticed, extendstransversely to the axis of the opening 2, need not necessarily be of adiameter requisite to form a snug fit of the shaft therein, as theeffect of the locking piece when moved to its locking position is towedge the parts firmly together irrespective of the looseness of theparts.

The locking piece R, embodying the cylindrical and conical surfacesmentioned, is shown as provided with a screw-thread lon its exteriorsurface the diameter of this looking piece and the coarseness of thepitch of its thread or threads will be such as to insure ample strengthto withstand the strain to which the parts may be subjected. In theconstruction illustrated, the top surface of the thread 4': upon thelocking piece R constitutes a portion of the surface of a cylinder; thatis, the stock in which the thread is formed is cylindrical from end toend. This surface at the top of the thread constitutes the mentionedcylindrical surface, designated for reference herein by P. The core orbody of the locking piece, however, tapers from one end to the other,the thread in this instance being deeper at the entering end of thescrew than at the opposite end. The surface of this core; that is, thesurface at the bottom of the thread, forms the mentioned conicalsurface, which is designated for reference herein by 4 It is evidentfrom the foregoing description that if the thread-sections upon one ofthe parts to be connected, and which serve to effect the longitudinalmovement of the looking piece when the same is rotated, are made of adepth not less than the minimum depth of the thread on the locking pieceit, nor greater than the maximum depth of such thread, that the tops of)these thread-sections will bed against or contact with the conicalsurface 4 at the bottom of the thread on the locking piece and as thelatter is moved inward result in a slight lateral movement of the piece.Hence, owing to the tapering body of the locking piece, the length wisemovement of this piece will be accompanied by its slight lateralmovement. These mentioned thread-sections are, in the present instance,formed in the part opposite to the arm or crank, see the thread-sectionsformed in the surface of the concave recess 6 in the shaft S disposed inline with the bore of opening in the arm. The thrust arising from thelateral movement of the locking piece it is taken by the oppositepark-that is, the arm W, and preferably the surfaces between which thisthrust or pressure is exerted are cylindrical so as not to render thereliability of the fastening device dependent upon an exact position ofthe crank or arm with reference to the shaft. As before stated, thelocking-piece R is of substantially uniform diameter from end to end ofthe thread, as measured across the top of the thread, and to render thetop surface only of this thread operative as a thrust surface the boreof the opening 2 in the arm or crank for the locking-piece may becylindrical and is preferably unprovided with a thread orthread-sections, permitting, thus, the 'top of the thread on the lockingpiece to impinge against its surface. Hence the operative contact, andby this expression 1 mean the contact to which the principle of theinvention may be referred, is, in the present embodiment, upon one side,cylinder to cylinder, and upon the other a wedging or trans verse actionis present. It is not important, therefore, in assembling andreassembling the parts that they should always be located in identicallythe same relative position to render the present fastening deviceeffective as such, although by the use of this invention the parts maybe secured one to the other with great precision. This permissible variation in position with attendant uniformity in attachment is especiallydesirable in the sepuring of small machine parts one to the ot ier.

Having described my invention, I claiin 1. In a two-part fasteningdevice, the combination with a locking piece having a cylindrical and aconical surface both spirally arranged, of a part having intersectingtransverse openings with smooth bores, one for the reception of the partto be connected to the mentioned part, and the other for the lockingpiece, and the connected part, which has an operative surface spirallyarranged.

2. In a two-part fastening device, the combination with a locking piecehaving a conical and a cylindrical surface diametrically opposite eachother and at different distances from the center of the piece, of a parthaving intersecting transverse openings with smooth bores, one for thereception of the part to be connected to the mentioned part and theother for the locking piece, and the connected part having an operativesurface spirally arranged.

3. In a two-part fastening device, the coinhination with a screw-likelocking piece having cylindrical and tapering operative surfacesspirally arranged with respect to the axis of the screw, of a parthaving intersect ing openings, one for the reception of the part to beconnected to the mentioned part and the other for the locking piece, andthe con nected part, which has an operative surface spirally arranged.

t. In a two-part fastening device, the combination with a screw-likelocking piece having cylindrical and tapering operative surfacesspirally arranged with res; ect to the axis of the screw, of a pa thaving intersecting transverse openii'igs, one for the reception of thepart to be connected to the mentioned partand the other for the lockingpiece, and the connected part, which has an operative surface spirallyarranged.

5. in a two-part fastening device, the coinhina tion with a screw-likelocking piece having a greater depth of thread at the entering end ofthe screw than at the other end and also having one of its operativesurfaces spirally arranged with respect to the axis of the screw, of apart having intersecting transverse openings, one for the reception ofthe part to be connected to the mentioned part, and the other for thelocking piece, and the connected part, which has an operative surfacespirally arranged.

6. In a two-part fastening device, the combination with a screw-likelocking piece having a greater depth of thread at the entering end ofthe screw than at the other end and also having one of its operativesurfaces spirally arranged with respect to the axis of the screw, of apart having intersecting transverse openings with sinooth cylindricalbores, one for the reception of the part to be connected to thementioned part, and the other for the locking piece, and the connectedpart, which has an operative surface spirally arranged.

7. In a two-part fastening device, the combination with a locking piece,of a part to be connected having an operative surface spirally arranged,a part having intersecting transverse openings, one for the reception ofthe part to be connected to the mentioned part and the other for thelocking piece, the conta-ctual surface along one side of the lockingpiece being inclined to the axis of the locking piece, while thecorresponding surface along the diametrically opposite side thereof inthe same longitudinal zone is substantially parallel to said axis, andthe two said contactual surfaces being disposed at relatively differentdistances from the axis of the locking piece.

8. In a two-part fastening device, the combination with a lockingdevice, of a part to be connected having an operative surface spirallyarranged, a part having intersecting transverse openings, one for thereception of the part to be connected to the mentioned part and theother for the locking piece, the contactual surface along one side ofthe locliing piece being curved and inclined to the axis of the lockingpiece, while the correspondin surface along the diametrically oppositeside thereof in the same longitudinal Zone is cylindrical, and the twosaid con tactual surfaces being disposed at relatively diil'erentdistances from the axis of the lock ing piece.

FRANCIS H. RICHARDS. Witnesses:

O. A. \VEED, O. E. Voss.

